Incidence, Subtypes, Risk factors, and Outcome of Delirium: A Prospective Observational Study from Indian Intensive Care Unit

Background

Delirium is a common, under-recognized, and often fatal condition in critically ill patients, characterized by acute disorder of attention and cognition. The global prevalence varies with a negative impact on outcomes. A paucity of Indian studies exists that have systematically assessed delirium.

Objective

A prospective observational study designed to determine the incidence, subtypes, risk factors, complications, and outcome of delirium in Indian intensive care units (ICUs).

Patients and methods

Among 1198 adult patients screened during the study period (December 2019-September 2021), 936 patients were included. The confusion assessment method score (CAM-ICU) and Richmond agitation sedation scale (RASS) were used, with additional confirmation of delirium by the psychiatrist/neurophysician. Risk factors and related complications were compared with a control group.

Results

Delirium occurred in 22.11% of critically ill patients. The hypoactive subtype was the most common (44.9%). The risk factors recognized were higher age, increased acute physiology and chronic health evaluation (APACHE-II) score, hyperuricemia, raised creatinine, hypoalbuminemia, hyperbilirubinemia, alcoholism, and smoking. Precipitating factors included patients admitted on noncubicle beds, proximity to the nursing station, requiring ventilation, as well as the use of sedatives, steroids, anticonvulsants, and vasopressors. Complications observed in the delirium group were unintentional removal of catheters (35.7%), aspiration (19.8%), need for reintubation (10.6%), decubitus ulcer formation (18.4%), and high mortality (21.3% vs 5%).

Conclusion

Delirium is common in Indian ICUs with a potential effect on length of stay and mortality. Identification of incidence, subtype, and risk factors is the first step toward prevention of this important cognitive dysfunction in the ICU.

How to cite this article

Tiwari AM, Zirpe KG, Khan AZ, Gurav SK, Deshmukh AM, Suryawanshi PB, et al. Incidence, Subtypes, Risk factors, and Outcome of Delirium: A Prospective Observational Study from Indian Intensive Care Unit. Indian J Crit Care Med 2023;27(2):111-118.

Pulmonary embolism presenting as delirium: an acute confusional state in an elderly patient-a case report

Background

Large numbers of elderly patients are admitted to hospitals in acute confusional states. In many, the underlying causes are easily found; in some, correct diagnosis is difficult. Pulmonary embolism (PE), the most serious clinical presentation of venous thromboembolism, is often misdiagnosed because of its non-specific features including delirium.

Case presentation

A 73-year-old woman was admitted to our hospital in a confused state with no obvious risk factors of PE. D-dimer levels were elevated and contrast-enhanced high-resolution computed tomography (HRCT) of the chest confirmed the diagnosis of PE. She was treated with enoxaparin and discharged on dabigatran. Her symptoms had resolved at the time of discharge, and she has been stable for over three month's follow-up visit.

Conclusion

PE should be regarded as a differential in elderly patients with an acute confusional state despite the absence of obvious risk factors. Investigating for and treating when confirmed may save a life.

Delirium in geriatric patients

Delirium is the most common acute disorder of cognitive function in older patients. Delirium is life threatening, often under-recognized, serious, and costly. The causes are multifactorial, with old age and neurocognitive disorders as the main risk factors. Etiologies are various and multifactorial, and often related to acute medical illness, adverse drug reactions, or medical complications. To date, diagnosis is clinically based, depending on the presence or absence of certain features. In view of the multifactorial etiology, multicomponent approaches seem most promising for facing patients’ needs. Pharmacological intervention, neither for prevention nor for treatment, has been proven effective unanimously. This article reviews the current clinical practice for delirium in geriatric patients, including etiology, pathophysiology, diagnosis, prognosis, treatment, prevention, and outcomes.

Delirium disorder: Unity in diversity

OBJECTIVE

The first objective of this review is to explore the factors that have led to and maintain the division between delirium and acute encephalopathy. The second is to explore the value of harmonizing them through the model of delirium disorder.

METHOD

This narrative review outlines major distinctions between delirium and acute encephalopathy. It also compares them with the model of delirium disorder, which seeks not only to integrate them but also to offer a broader palette of treatment targets.

RESULTS

Delirium implies an underlying acute encephalopathy, whereas acute encephalopathy presents as a spectrum from subsyndromal delirium to coma. Key factors that differentiate these two models include tradition, nuances of the models themselves, linguistic connotations, evoked responses from clinicians, implications of preventability and responsibility, cultural perceptions of non-pharmacological vs pharmacological interventions and economic incentives. A validated set of pathophysiological subtypes may ultimately help link the delirium-spectrum phenotype with various acute encephalopathies.

CONCLUSIONS

Developing a coherent clinical and scientific approach to this set of conditions demands that we first develop a coherent understanding of the conditions themselves and how they relate to one another. Such an approach must embrace the tension between a convergent phenotype and its diverse biological underpinnings.

Prevalence and clinical correlates of non-convulsive status epilepticus in elderly patients with acute confusional state: A systematic literature review

Non-convulsive status epilepticus (NCSE) is a potentially treatable condition that poses considerable diagnostic challenges. NCSE is thought to be more common in the elderly than in the general population, however additional diagnostic challenges complicate its recognition in older patients, because of the wide differential diagnosis with common underlying causes of acute confusional state in this age group. We set out to review the existing evidence on the clinical correlates of NCSE in the elderly population. A systematic literature review was conducted according to the methodological standards outlined in the PRISMA statement to assess the clinical correlates of NCSE in patients aged 60 or older. Our literature search identified 11 relevant studies, which confirmed that the incidence of NCSE increases with age, in particular with regard to focal forms with impairment of consciousness. Female gender, history of epilepsy (or a recently witnessed seizure with motor features), and abnormal ocular movements appeared to correlate with the diagnosis of NCSE in the elderly, prompting prioritization of electroencephalography tests for diagnostic confirmation. Epidemiological data in the elderly vary widely because of the heterogeneity of definitions and diagnostic criteria applied across different studies. Based on our findings, it is recommended to keep a low threshold for requesting electroencephalography tests to confirm the diagnosis of NCSE in elderly patients with acute confusional state, even in the presence of a presumed symptomatic cause.

Louis Delasiauve (1804-1893), an alienist at the dawn of epileptology and pediatric psychiatry

This paper aims to honor the memory of the alienist Louis Delasiauve (1804-1893). His classification of the different types of epilepsy based on clinical symptoms is still relevant today and made him a precursor of contemporary epileptology. In 1851, Delasiauve clinically and etiologically isolated 'acute mental confusion' (acute confusional state) from all other forms of dementia. Never deviating from his republican and progressive ideals, he devoted himself throughout the 19th century to treating those insane asylum patients who received the poorest care: epileptics and children with intellectual disabilities. Studying functional cognitive disability as well as mental disability secondary to congenital malformations, Delasiauve developed a novel specific form of pedagogy to deal with delays in cognitive development. This made him one of the initiators of institutional pediatric psychiatry. His ideas would be carried forward by his favorite student, Désiré-Magloire Bourneville (1840-1909). Committed to social welfare, Delasiauve worked relentlessly to improve access to healthcare for the least fortunate throughout France. As a passionate supporter of universal, free and secular education, he participated in a major movement away from religious establishments that involved opening a public school in every French canton.

Characterizing and predicting rates of delirium across general hospital settings

OBJECTIVE

To better understand variation in reported rates of delirium, this study characterized delirium occurrence rate by department of service and primary admitting diagnosis.

METHOD

Nine consecutive years (2005-2013) of general hospital admissions (N=831,348) were identified across two academic medical centers using electronic health records. The primary admitting diagnosis and the treating clinical department were used to calculate occurrence rates of a previously published delirium definition composed of billing codes and natural language processing of discharge summaries.

RESULTS

Delirium rates varied significantly across both admitting diagnosis group (X²₁₀=12786, p<0.001) and department of care (X²₆=12106, p<0.001). In both cases obstetrical admissions showed the lowest incidences of delirium (86/109764; 0.08%) and neurological admissions the greatest (2851/25450; 11.2%). Although the rate of delirium varied across the two hospitals the relative rates within departments (r=0.96, p<0.001) and diagnostic categories (r=0.98, p<0.001) were consistent across the two institutions.

CONCLUSIONS

The frequency of delirium varies significantly across admitting diagnosis and hospital department. Both admitting diagnosis and department of care are even stronger predictors of risk than age; as such, simple risk stratification may offer avenues for targeted prevention and treatment efforts.

Stroke severity predicts poststroke delirium and its association with dementia: Longitudinal observation from a low income setting

OBJECTIVE

The effect of delirium on stroke outcome has not been quantified in sub-Saharan Africa. We investigated the prevalence of delirium occurring within one week of stroke in Nigerian survivors and its association with dementia and mortality at 3months.

METHODS

Delirium was ascertained after repeated assessments within one week of stroke using the Confusion Assessment Method. Demographic and clinical characteristics, stroke severity, current and pre-morbid cognitive functioning were also assessed. Participants were then followed up for 3months using culturally-validated neuropsychological tools. Probable dementia was ascertained according to the National Institute of Neurological Disorders and Stroke (NINDS-AIREN) criteria. Associations were investigated using both binomial and multinomial logistic regression analyses and presented as odds ratios (O.R) and relative risk ratios (RRR).

RESULTS

Of 101 consenting stroke survivors, 99 had two assessments for delirium within one week of the stroke. Delirium was present in 33.3% of stroke survivors (65.6% hypoactive, 21.9% hyperactive, and 12.1% mixed type). Having a severe stroke was associated with delirium (O.R=6.2, 95% C.I=1.1-13.8) after adjusting for age, gender, education and economic status, lifestyle factors, multimorbidities and laterality. At follow-up, those with severe stroke had a stronger association between delirium and dementia (RRR=4.3, 95% C.I=1.2-15.6) or death (RRR=3.7, 95% C.I=1.1-12.1).

CONCLUSION

Delirium, in this sub-Saharan African sample, was already present in about one-third of survivors within one week of stroke. Survivors of severe stroke are at higher risk of delirium and its complications, and could be important target for delirium preventive interventions.

Neurological Manifestations in Systemic Lupus Erythematosus: A Single Centre Study from North East India

INTRODUCTION

Neurological manifestations although common in Systemic Lupus Erythematosus (SLE), are often not recognized due to their diversed and varied presentation. Therefore, the study was planned to highlight the pattern of neurological involvement in SLE to help in early recognition.

AIM

To study the pattern of neurological involvement in SLE and its correlation with disease activity and different investigation.

MATERIALS AND METHODS

This hospital based prospective observational study was carried out from August 2009 to July 2010. Diagnosed cases of SLE [based upon American Rheumatism Association (ARA) criteria] who presented with neurological manifestations at the time of diagnosis or develop during the course of the disease were included in the study. They were assessed clinically and investigated with neuroimaging and neurophysiological tests as applicable.

RESULTS

In total, 52 consecutive patients with SLE were evaluated, 92% were female. The most common age group was 21 to 25 years. Nervous system involvement was found in 19 (36.54%) patients. Cognitive impairment was the most frequent manifestation, present in 11 (57.89%) patients followed by seizure disorder in eight patients (42.1%). Peripheral neuropathy was diagnosed in eight (42.1%), acute confusional state in six (31.57%) and headache and depression was diagnosed in five (26.31%) patients each. Less common manifestations were psychosis, movement disorder and aseptic meningitis. Percentage of neurological manifestations directly correlated with disease activity. A significant difference was found in Systemic Lupus Erythematosus Disease Activity Index (SLEDAI) score between the patients with Neuro Psychiatric Systemic Lupus Erythematosus (NPSLE) and those without NPSLE (32.42±16.34 Vs 17.3±10.6).

CONCLUSION

Neurological involvement in SLE is seen relatively early in the course of the disease with cognitive impairment being the most common manifestation and correlate with disease activity.

Anti-N-Methyl-D-Aspartate Receptor Encephalitis in HIV Infection

Anti-N-methyl-D-aspartate receptor (anti-NMDAR) encephalitis is a rare condition characterized by emotional and behavioral disturbances, dyskinesias, and extrapyramidal signs. It occurs in young women of reproductive age and is classically described as a paraneoplastic phenomenon. We present a 36-year-old, HIV-positive female who was admitted to the hospital in an acute confusional state, with a stiff posture, periods of motor agitation, and myoclonic jerks of the hands. Her mental state progressively deteriorated. Without evidence of infection, the presence of anti-NMDAR antibodies both in serum and cerebrospinal fluid clinched the diagnosis of autoimmune encephalitis. No evidence of neoplastic disease was found, and the beneficial response to immunosuppressive therapy was exceptional. This is the first report of anti-NMDAR encephalitis in an HIV-infected individual, reminding us that autoimmune encephalitis should be included in the differential diagnosis of a young patient presenting in an acute confusional state.

Comparative Study of Delirium in Emergency and Consultation Liaison- A Tertiary Care Hospital Based Study in Northern India

INTRODUCTION

Delirium is an acute and often fluctuating disturbance in level of consciousness and thought process (cognition) that develops over a short period of time and is a significant change from previous level of functioning. Its prevalence increases with age, complexity of medical co- morbidities and number of medications prescribed.

AIM

To compare the cause and severity of delirium in patients in emergency and consultation liaison psychiatry group.

MATERIALS AND METHODS

A cross-sectional, tertiary care hospital based study was conducted on the patients who presented with delirium from emergency department (50) and consultation-liaison psychiatry groups (50), over a period of one year. The diagnosis was made on the basis of DSM- 5 criteria. The Delirium Rating Scale (DRS-R-98) was applied to know the severity of delirium, cognitive and non-cognitive symptoms of delirium in patients. The results were subjected to appropriate statistical analysis.

RESULTS

In emergency group, 42% patients had metabolic abnormalities, while in consultation-liaison, 38% patients had hyponatremia and hypokalemia and the difference was found to be statistically non-significant (p>0.05). In emergency group, 21(42%) patients were diagnosed as delirium due to other medical condition, followed by 13 (26%) and 8(16%) patients, who were diagnosed as delirium due to multiple aetiologies and substance intoxication each respectively. In only 33(66%) cases in consultation liaison group patients had delirium secondary to other medical conditions. As per DRS-R98 Scale, mean severity score was found to be statistically significant (p<0.05) in consultation liaison group as compared to emergency department group (p> 0.05).

CONCLUSION

Delirium is multifactorial aetiological disease, with variable but preventable outcome. Approach should be aimed at finding the treatable causes to reduce morbidity and mortality.

Emergency electroencephalogram: Usefulness in the diagnosis of nonconvulsive status epilepticus by the on-call neurologist

INTRODUCTION

We aim to describe the use of emergency electroencephalogram (EmEEG) by the on-call neurologist when nonconvulsive status epilepticus (NCSE) is suspected, and in other indications, in a tertiary hospital.

SUBJECTS AND METHODS

Observational retrospective cohort study of emergency EEG (EmEEG) recordings with 8-channel systems performed and analysed by the on-call neurologist in the emergency department and in-hospital wards between July 2013 and May 2015. Variables recorded were sex, age, symptoms, first diagnosis, previous seizure and cause, previous stroke, cancer, brain computed tomography, diagnosis after EEG, treatment, patient progress, routine control EEG (rEEG), and final diagnosis. We analysed frequency data, sensitivity, and specificity in the diagnosis of NCSE.

RESULTS

The study included 135 EEG recordings performed in 129 patients; 51.4% were men and their median age was 69 years. In 112 cases (83%), doctors ruled out suspected NCSE because of altered level of consciousness in 42 (37.5%), behavioural abnormalities in 38 (33.9%), and aphasia in 32 (28.5%). The EmEEG diagnosis was NCSE in 37 patients (33%), and this was confirmed in 35 (94.6%) as the final diagnosis. In 3 other cases, NCSE was the diagnosis on discharge as confirmed by rEEG although the EmEEG missed this condition at first. EmEEG performed to rule out NCSE showed 92.1% sensitivity, 97.2% specificity, a positive predictive value of 94.6%, and a negative predictive value of 96%.

CONCLUSIONS

Our experience finds that, in an appropriate clinical context, EmEEG performed by the on-call neurologist is a sensitive and specific tool for diagnosing NCSE.

The short-term and long-term relationship between delirium and cognitive trajectory in older surgical patients

INTRODUCTION

As the relationship between delirium and long-term cognitive decline has not been well-explored, we evaluated this association in a prospective study.

METHODS

SAGES is an ongoing study involving 560 adults age 70 years or more without dementia scheduled for major surgery. Delirium was assessed daily in the postoperative period using the Confusion Assessment Method. General Cognitive Performance (GCP) and the Informant Questionnaire for Cognitive Decline in the Elderly were assessed preoperatively then repeatedly out to 36 months.

RESULTS

On average, patients with postoperative delirium had significantly lower preoperative cognitive performance, greater immediate (1 month) impairment, equivalent recovery at 2 months, and significantly greater long-term cognitive decline relative to the nondelirium group. Proxy reports corroborated the clinical significance of the long-term cognitive decline in delirious patients.

DISCUSSION

Cognitive decline after surgery is biphasic and accelerated among persons with delirium. The pace of long-term decline is similar to that seen with mild cognitive impairment.

Transverse myelitis extended to disseminated encephalitis in systemic lupus erythematosus: Histological evidence for vasculitis

A 42-year-old woman was admitted due to systemic lupus erythematosus complicated with glomerulonephritis and pulmonary hypertension. During the treatment for these complications, she presented motor paresis and sensory loss caused by transverse myelitis. In spite of methyl prednisolone pulse therapy, she further developed acute confusional state due to disseminated encephalitis and fell into respiratory arrest. On laboratory examination, elevation of anti-NR2 antibodies in serum as well as in cerebrospinal fluid was noted. Although she recovered from the disseminated encephalitis after extensive treatment with high doses of corticosteroid and intravenous cyclophosphamide, she suddenly died of pulmonary hypertension. Autopsy findings confirmed the presence of liquefaction necrosis in the entire circumference of the whole spinal cord along with intimal hyperplasia and obliteration of the small arteries, accompanied by mononuclear cell infiltration and disruption of internal elastic lamina. It is therefore most likely that our patient developed longitudinal transverse myelitis through spinal cord vasculitis, which extended to brainstem and brain parenchyma, leading to the development of disseminated encephalitis.

Acute confusional state/delirium: An etiological and prognostic evaluation

Introduction:

Acute confusional state/delirium is a frequent cause of hospital admission, in the elderly. It is characterized by an acute fluctuating impairment of cognitive functions and inattention. Recognition and prompt treatment is crucial to decrease the morbidity and mortality associated with it.

Materials and Methods:

In this retrospective study, we determined the etiology and prognostic factors of an acute confusional state. A total of 52 patients of acute confusional state were clinically evaluated. All patients were also subjected to a battery blood biochemical examination, cerebrospinal fluid analysis and neuroimaging. Disability was assessed by using modified Barthel index (MBI). Patients were followed-up for 3 months.

Results:

The mean age of our cohort was 65.04 ± 10.6 years. 32 (61.5%) patients were male. In 33 patients, we were able to identify possible precipitating cause of an acute confusional state. In the rest of the patients results of all the tests were normal. Leukocytosis and hyponatremia were frequent factors associated with delirium. The mean duration of the hospital stay was 10.73 ± 3.6 days (range 5-21 days). Patients with an abnormal work-up (possible precipitating cause) had significantly lower mortality, less duration of hospital stay and less severe disability after 3 months. Age, underlying illness, serum creatinine, abnormal neuroimaging and MBI were identified as a significant prognostic indicator. 18 (34.6%) of our patients died, of these in 10 patients we could not find a precipitating cause.

Conclusion:

Patients, in whom a cause was found out, had better prognosis in terms of lesser mortality and the duration of hospital stay.

Delirium in adult patients receiving palliative care: a systematic review of the literature

Delirium in palliative care patients is common and its diagnosis and treatment is a major challenge. Our objective was to perform a literature analysis in two phases on the recent scientific evidence (2007-2012) on the diagnosis and treatment of delirium in adults receiving palliative care. In phase 1 (descriptive studies and narrative reviews) 133 relevant articles were identified: 73 addressed the issue of delirium secondarily, and 60 articles as the main topic. However, only 4 prospective observational studies in which delirium was central were identified. Of 135 articles analysed in phase 2 (clinical trials or descriptive studies on treatment of delirium in palliative care patients), only 3 were about prevention or treatment: 2 retrospective studies and one clinical trial on multicomponent prevention in cancer patients. Much of the recent literature is related to reviews on studies conducted more than a decade ago and on patients different to those receiving palliative care. In conclusion, recent scientific evidence on delirium in palliative care is limited and suboptimal. Prospective studies are urgently needed that focus specifically on this highly vulnerable population.

Incidence and predictive factors of delirium in hospitalised neurological patients

INTRODUCTION

Delirium is a condition with a high prevalence in hospitalised patients (10%-30%), and it has important prognostic implications. There are few prospective studies of the incidence of delirium in Spain, and most of these were carried out in surgical wards or intensive care units. Our objective is to calculate the incidence of delirium in a neurological department and describe characteristics of affected patients.

METHODS

Longitudinal descriptive study including all patients admitted to the neurology department in an 8-week period. The CAM score for diagnosing delirium was recorded on the first, second and fifth day of hospitalisation and we recorded demographic data, medical history, analytical data (including inflammatory markers), use of anticholinergic treatments, cognitive and functional state at admission, reason for admission, length of stay, and other events during hospitalisation.

RESULTS

We studied 115 patients and found an incidence of delirium of 16.52%. There was a significant correlation between delirium and age, cognitive state at admission according to the Pfeiffer test, functional situation at admission according to the Canadian Neurological Scale, kidney failure, history of stroke, anticholinergic treatment, erythrocyte sedimentation rate, and C-reactive protein. These patients were also hospitalised for longer periods of time.

CONCLUSIONS

These results confirm a high incidence of delirium in our geographical area. Although additional studies with larger samples are needed, we would like to emphasise the importance of several risk factors which may enable early detection of patients who are at risk for developing delirium during hospitalisation. This would permit preventive action and early treatment for these patients.